Installing fan support box when joists don't touch drywall


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Old 07-22-21, 09:42 PM
J
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Installing fan support box when joists don't touch drywall

I'm replacing an old florescent light fixture on the first floor where there was no junction box. I want to install a fan rated box and brace (no access from above) though I'm only doing a light fixture right now, I want to have the option for something heavier later. Got a box/brace kitcut the hole in the ceiling, then found a problem. The drywall isn't attached to the joists in the ceiling. Instead, there are 2x4s laying flat under the joists, running perpendicular. This means the bottom of the joists are a good 1.5" above the sheetrock, so I can't attach the brace to those and have the box accessible outside the drywall. The perpendicular 2x4s aren't tall enough to accommodate the bracket either.
Any ideas on how to mount a junction box in this situation? Because of the location of joists and the 2x4s, mounting a box directly to those isn't an option.

Thanks
 
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Old 07-22-21, 09:57 PM
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Put perpendicular blocking between the joists that rests on the drywall or fill the void under the joists with 2x2 or 2x4.
 
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Old 07-22-21, 11:27 PM
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It sounds like 2x4's were installed as furring over the existing ceiling for new sheetrock. Why ?

Typically furring strips aren't strong enough. 2x4's should be.
You could mount a box to the bottom of the 2x4 furring if it were in the right location.
I would want to add an extra screw or two from the furring strip to the original joists.

As I think xSleeper was mentioning.... you may have to install your own 2x4 furring in the needed location.

Then you'd use a fan rated pancake box.

 
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Old 07-23-21, 04:12 PM
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Thanks for the ideas!
 
 

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